1. Field of the Invention
The present invention relates to a support structure for supporting a foamable material on a hollow structural member, and more particularly to a support structure for supporting a foamable material in a cavity of a closed box-like hollow structural member constituted of a plurality of pieces of plates or panels, such as a pillar, a rocker panel and a roof side panel of a vehicle body, in order that the foamable material blocks the cavity of the hollow structural member to increase damping powers, sound insulation powers and other powers of the hollow structural member when it is foamed by external heating.
2. Description of the Prior Art
FIG. 13 exemplarily shows a conventional support structure. In this support structure, to support a foamable material 121 in a cavity 106 of a pillar 101 as a hollow structural member, a bolt 111 having a threaded section 111a is mounted on an inner pillar panel 102 so that the threaded section 111a is projected into the cavity 106 at a desired length. The threaded section 111a is then provided with a washer 120. The foamable material 121 engages the threaded section 111a by sticking so as to be seated on the washer 120. Thus, the foamable material 121 is supported in a cavity 106 of the pillar 101.
Such a support structure of the foamable material as described above is disclosed, for example, in Japanese Laid-Open Patent Publication No. 2-276836 (corresponding to British Patent Application No. 8903211.4).
In the above-noted conventional support structure of the foamable material in which the foamable material 121 engages the threaded section 111a of the bolt 111 projected into the cavity 106 of the pillar 101, the foamable material 121 is unrestrictively expanded in all directions when it is foamed and expanded by heating externally of the pillar 101. Therefore, as shown in FIG. 14, the foamable material 121, when heated by external heating, is foamed and expanded to form a foamed product 122 which is unnecessarily elongated in a longitudinal direction of the the cavity 106.
Thus, to sufficiently block the cavity 106 by the foamed product 122, the foamable material 121 has to be extremely increased in amount. This may lead to increased cost.